@ainc/script/src/helpers/module-paths-transformer.ts

Script compiler for typescript

/**
 *****************************************
 * Created by edonet@163.com
 * Created on 2021-07-07 22:35:20
 *****************************************
 */
'use strict';


/**
 *****************************************
 * 加载依赖
 *****************************************
 */
import * as ts from 'typescript';
import { cwd } from '@ainc/fs/dist/cwd';
import { dirname } from '@ainc/fs/dist/dirname';
import { relative } from '@ainc/fs/dist/relative';
import { isBuiltinModule } from './isBuiltinModule';


/**
 *****************************************
 * 扩展类型
 *****************************************
 */
declare module 'typescript' {
    interface SourceFile {
        resolvedModules: ts.ESMap<string, ts.ResolvedModuleFull>;
    }
}


/**
 *****************************************
 * 定义转换器
 *****************************************
 */
export function transformer(context: ts.TransformationContext): ts.Transformer<ts.SourceFile> {
    const calls = ['import', 'require', 'require.resolve'];
    const factory = context.factory;
    const compilerOptions = context.getCompilerOptions();

    // 转换文件节点
    return (sourceFile: ts.SourceFile) => {
        const { fileName, resolvedModules } = sourceFile;
        const file = cwd(fileName);
        const dir = dirname(file);

        // 解析模块
        function resolveModule(id: string): void | ts.ResolvedModuleFull {
            const cached = resolvedModules.get(id);

            // 返回缓存
            if (cached) {
                return cached;
            }

            // 解析模块
            const { resolvedModule } = ts.resolveModuleName(id, file, compilerOptions, ts.sys);

            // 解析失败
            if (!resolvedModule) {
                return;
            }

            // 更新缓存
            resolvedModules.set(id, resolvedModule);

            // 返回结果
            return resolvedModule;
        }

        // 访问模块节点
        function visitModuleSpecifier(node: ts.Node): ts.Node {
            if (ts.isStringLiteral(node)) {
                const { text } = node || {};

                // 不处理相对模块
                if (text && !isBuiltinModule(text) && text.charAt(0) !== '.') {
                    const resolved = resolveModule(text);

                    // 不处理外部模块
                    if (resolved && !resolved.isExternalLibraryImport) {
                        const { resolvedFileName, extension } = resolved;

                        // 生成节点
                        return factory.createStringLiteral(
                            relative(dir, cwd(resolvedFileName.slice(0, - extension.length)))
                        );
                    }
                }
            }

            // 返回原节点
            return node;
        }

        // 访问调用节点
        function visitCallDeclaration(node: ts.Node): ts.Node {
            if (ts.isCallExpression(node)) {
                const id = node.expression.getText();

                // 匹配函数名且只有一个参数时处理
                if (calls.includes(id) && node.arguments.length === 1 && ts.isStringLiteral(node.arguments[0])) {
                    return factory.updateCallExpression(
                        node,
                        node.expression,
                        node.typeArguments,
                        ts.visitNodes(node.arguments, visitModuleSpecifier),
                    );
                }
            }

            // 访问子节点
            return ts.visitEachChild(node, visitCallDeclaration, context);
        }

        // 访问文件子节点
        function visitSourceFile(node: ts.Node): ts.Node {

            // 处理载入节点
            if (ts.isImportDeclaration(node)) {
                return ts.visitEachChild(node, visitModuleSpecifier, context);
            }

            // 处理抛出节点
            if (ts.isExportDeclaration(node)) {
                return ts.visitEachChild(node, visitModuleSpecifier, context);
            }

            // 返回节点
            return visitCallDeclaration(node);
        }

        // 访问文件子节点
        return ts.visitEachChild(sourceFile, visitSourceFile, context);
    };
}